Hey there @stevesally welcome to the community!
The call to /logout should delete your user’s session cookie (Auth0) - Are you able to elaborate a bit more on your use case?
- Are you using an SDK?
- Is there an iFrame involved?
- Do you see this in a particular browser or multiple?
The more information you can provide the better! Here’s some supporting documentation on Logout and sessions with Auth0.
Keep us posted 